661015105 has 4 divisors (see below), whose sum is σ = 793218132. Its totient is φ = 528812080.

The previous prime is 661015087. The next prime is 661015123. The reversal of 661015105 is 501510166.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (661015087) and next prime (661015123).

It can be written as a sum of positive squares in 2 ways, for example, as 127035441 + 533979664 = 11271^2 + 23108^2 .

It is not a de Polignac number, because 661015105 - 2²⁹ = 124144193 is a prime.

It is a super-2 number, since 2×661015105² = 873881938076322050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661015105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66101506 + ... + 66101515.

It is an arithmetic number, because the mean of its divisors is an integer number (198304533).

Almost surely, 2^661015105 is an apocalyptic number.

It is an amenable number.

661015105 is a deficient number, since it is larger than the sum of its proper divisors (132203027).

661015105 is a wasteful number, since it uses less digits than its factorization.

661015105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132203026.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 661015105 is about 25710.2140208906. The cubic root of 661015105 is about 871.1049091908.

The spelling of 661015105 in words is "six hundred sixty-one million, fifteen thousand, one hundred five".